Editing George B. McClellan (section)

===Peninsula campaign===
[[File:Peninsula Campaign March-May 1862.png|thumb|Peninsula Campaign, March–May 1862{{legend-line|2px #ff0000 solid|Confederate}}{{legend-line|2px #0000ff solid|Union}}]]
[[File:Seven Days Battles overview.pdf|thumb|Seven Days Battles, June 25 – July 1, 1862]]
McClellan's army began to sail from [[Alexandria, Virginia|Alexandria]] on March 17. It was an armada that dwarfed all previous American expeditions, transporting 121,500 men, 44 artillery batteries, 1,150 wagons, over 15,000 horses, and tons of equipment and supplies. An English observer remarked that it was the "stride of a giant".<ref name="bVoLi" /> The army's advance from [[Fort Monroe]] up the [[Virginia Peninsula]] proved to be slow. McClellan's plan for a rapid seizure of [[Yorktown, Virginia|Yorktown]] was foiled by the removal of 1st Corps from the Army of the Potomac for the defense of Washington. McClellan had hoped to use the 1st Corps to capture [[Gloucester Point, Virginia|Glouchester Point]] and thus outflank the Confederate position. When he discovered that the Confederates had fortified a line across the Peninsula he hesitated to attack and instead "played it safe". As Swinton notes: <blockquote>It is possible, however—and there is a considerable volume of evidence bearing upon this point—that General McClellan, during all the earlier portion of the month before Yorktown, had it in his mind, even without McDowell's corps, to undertake the decisive turning movement by the north side of the York. In this event, it would not only be in the direction of his plan to make no attack, but it would play into his hands that his opponent should accumulate his forces on the Peninsula. Yet this halting between two opinions had the result that, when he had abandoned the purpose of making the turning movement, it had become too late for him to make a direct attack.</blockquote> McClellan asked for the opinion of his chief engineer [[John G. Barnard]], who recommended against an assault. This caused him to decide on a siege of the city, which required considerable preparation.

McClellan continued to believe intelligence reports that credited the Confederates with two or three times the men they actually had. Early in the campaign, Confederate General [[John B. Magruder|John B. "Prince John" Magruder]] defended the Peninsula against McClellan's advance with a vastly smaller force. He created a false impression of many troops behind the lines and of even more troops arriving. He accomplished this by marching small groups of men repeatedly past places where they could be observed at a distance or were just out of sight, accompanied by great noise and fanfare.<ref name="Ysg22" /> During this time, General Johnston was able to provide Magruder with reinforcements, but even then there were far fewer troops than McClellan believed were opposite him.

After a month of preparation, just before he was to assault the Confederate works at Yorktown, McClellan learned that Johnston had withdrawn up the Peninsula towards [[Williamsburg, Virginia|Williamsburg]]. McClellan was thus required to give chase without any benefit of the heavy artillery so carefully amassed in front of Yorktown. The [[Battle of Williamsburg]] on May 5 is considered a Union victory—McClellan's first—but the Confederate army was not destroyed and most of their troops were successfully moved past Williamsburg to Richmond's outer defenses while the battle was waged and for several days thereafter.<ref name="naBsx" />

McClellan had also placed hopes on a simultaneous naval approach to Richmond via the [[James River (Virginia)|James River]]. That approach failed following the Union Navy's defeat at the [[Battle of Drewry's Bluff]], about {{convert|7|mi|km}} downstream from the Confederate capital, on May 15. Basing artillery on a strategic bluff high above a bend in the river, and sinking boats to create an impassable series of obstacles in the river itself, the Confederates effectively blocked this potential approach to Richmond.<ref name="zIGI0" />

McClellan's army moved towards Richmond over the next three weeks, coming to within {{convert|4|mi|km|spell=in}} of it. He established a supply base on the [[Pamunkey River]] (a navigable tributary of the [[York River (Virginia)|York River]]) at [[White House Landing, Virginia|White House Landing]] where the [[Richmond and York River Railroad]] extending to Richmond crossed, and commandeered the [[railroad]], transporting [[steam locomotive]]s and rolling stock to the site by barge.<ref name="OZxGk" />

On May 31, as McClellan planned an assault, his army was surprised by a Confederate attack. Johnston saw that the Union army was split in half by the rain-swollen [[Chickahominy River]] and hoped to [[defeat in detail|defeat it in detail]] at [[Battle of Seven Pines|Seven Pines]] and Fair Oaks. McClellan was unable to command the army personally because of a recurrence of malarial fever, but his subordinates were able to repel the attacks. Nevertheless, McClellan received criticism from Washington for not counterattacking, which some believed could have opened the city of Richmond to capture. Johnston was wounded in the battle, and General Robert E. Lee assumed command of the [[Army of Northern Virginia]]. McClellan spent the next three weeks repositioning his troops and waiting for promised reinforcements. As Lee recounted, McClellan was attempting to make "this a battle of posts" which would lock the Confederate army in an attritional battle with superior Union firepower.

At the end of June, Lee began a series of attacks that became known as the Seven Days Battles. The first major battle, at [[Battle of Beaver Dam Creek|Mechanicsville]], was poorly coordinated by Lee and his subordinates and resulted in heavy casualties for little tactical gain. However, the battle had a significant impact on McClellan's nerve. The surprise appearance of Maj. Gen. [[Stonewall Jackson]]'s troops in the battle (when they had last been reported to be many miles away in the [[Shenandoah Valley]]) convinced McClellan that he was even more outnumbered than he had thought. He reported to Washington that he faced 200,000 Confederates, perhaps due to a false report on the arrival of another Confederate army P.G.T. Beauregard. The number of men McClellan was actually faced varies, with Joseph Harsh in ''Confederate Tide Rising'' placing Lee's army at 112,220 men compared with the 105,857 under McClellan.

[[File:Battle of Gaines' Mill.png|thumb|left|Federal troops under heavy attack at the [[Battle of Gaines's Mill]], sketched by [[Alfred R. Waud]] and published in ''[[Harper's Weekly]]'', July 26, 1862]]
Lee continued his offensive at [[Battle of Gaines's Mill|Gaines's Mill]] to the east. That night, McClellan decided to withdraw his army to a safer base, well below Richmond, on a portion of the James River that was under control of the Union Navy. In doing so, Lee had assumed that the Union army would withdraw to the east toward its existing supply base and McClellan's move to the south delayed Lee's response for at least 24 hours.<ref name="SR0wF" /> Ethan Rafuse notes "McClellan's change of base to the James, however, thwarted Lee's attempt to do this. Not only did McClellan's decision allow the Federals to gain control of the time and place for the battles that took place in late June and early July, it enabled them to fight in a way that inflicted terrible beating on the Confederate army....More importantly, by the end of the Seven Days Battles, McClellan had dramatically improved his operational situation."<ref name="Xr7Wg" />

But McClellan was also tacitly acknowledging that he would no longer be able to [[investment (military)|invest]] Richmond, the object of his campaign; the heavy siege artillery required would be almost impossible to transport without the railroad connections available from his original supply base on the York River. In a telegram to Secretary of War [[Edwin Stanton]], reporting on these events, McClellan blamed the Lincoln administration for his reversals. "If I save this army now, I tell you plainly I owe no thanks to you or to any other persons in Washington. You have done your best to sacrifice this army."<ref name="ZodO4" /> Fortunately for McClellan, Lincoln never saw that inflammatory statement (at least at that time) because it was censored by the War Department telegrapher.

[[File:After Battle of Savage's Station.jpg|thumb|Wounded men after the [[Battle of Savage's Station]], one of the Seven Days Battles]]
McClellan was also fortunate that the failure of the campaign left his army mostly intact, because he was generally absent from the fighting and neglected to name any second-in-command who might direct his retreat.<ref name="GJIre" /> Military historian Stephen W. Sears wrote, "When he deserted his army on the [[Battle of Glendale|Glendale]] and [[Battle of Malvern Hill|Malvern Hill]] battlefields during the Seven Days, he was guilty of [[dereliction of duty]]. Had the Army of the Potomac been wrecked on either of these fields (at Glendale the possibility had been real), that charge under the Articles of War would likely have been brought against him."<ref name="1ycqP" /> In the battle of Glendale, McClellan was {{convert|5|mi|km|spell=in}} away behind Malvern Hill, without telegraph communications and too distant to command his army. In the battle of Malvern Hill, he was on a gunboat, the {{USS|Galena|1862|6}}, which at one point was {{convert|10|mi|km|spell=in}} away, down the James River.<ref name="KmOQD" /> In both battles, effective command of the army fell to his friend and [[V Corps (Union Army)|V Corps]] commander Brigadier General [[Fitz John Porter]]. When the public heard about the ''Galena'', it was yet another great embarrassment, comparable to the Quaker Guns at Manassas. Editorial cartoons published in the course of the 1864 presidential campaign lampooned McClellan for having preferred the safety of a ship while a battle was fought in the distance.<ref name="81vyb" />

McClellan was reunited with his army at Harrison's Landing on the James. Debates were held as to whether the army should be evacuated or attempt to resume an offensive toward Richmond. McClellan maintained his estrangement from Abraham Lincoln with his repeated call for reinforcements and by writing a lengthy letter in which he proposed strategic and political guidance for the war, continuing his opposition to abolition or seizure of slaves as a tactic. He concluded by implying he should be restored as general-in-chief, but Lincoln responded by naming Maj. Gen. [[Henry W. Halleck]] to the post without consulting, or even informing, McClellan.<ref name="yt1Na" /> Lincoln and Stanton also offered command of the Army of the Potomac to Maj. Gen. [[Ambrose Burnside]], who refused the appointment.<ref name="sK243" />

Back in Washington, a reorganization of units created the [[Army of Virginia]] under Maj. Gen. [[John Pope (general)|John Pope]], who was directed to advance toward Richmond from the northeast. McClellan, not wishing to abandon his campaign, delayed the return of the Army of the Potomac from the Peninsula enough so that the reinforcements arrived while the [[northern Virginia campaign]] was already underway. The Fifth Corps under Porter from the Army of the Potomac would serve with Pope during the campaign. A frustrated McClellan wrote to his wife before the battle, "Pope will be thrashed ... & be disposed of [by Lee]. ... Such a villain as he is ought to bring defeat upon any cause that employs him."<ref name="WEzI7" /> Lee had gambled on removing significant units from the Peninsula to attack Pope, who was beaten decisively at [[Second Bull Run]] in August.